Study On The Regulation Of Persulfate System And Catalytic Oxidation Performance Of Polycaffeic Acid Modified Material

The advanced catalytic oxidation method of persulfate activated by Fe²⁺is a convenient and environment-friendly technology.Focusing on the regulation of Fe²⁺catalytic oxidation,poly caffeic acid composite polypropylene nonwovens（PCA-PP）were prepared by mussel biomimetic chemical method to regulate the activation of iron on persulfate,so as to improve the utilization efficiency of Fe²⁺and reduce its quenching effect on free radicals in the process of Fe²⁺activated persulfate（PMS）.The modified materials were characterized by SEM,FTIR and XPS.The regulation effect of PCA-PP on iron activated PMS was explored.The mechanism of PCA-PP regulating the degradation of acid red B（ARB）by iron activated PMS was analyzed.The oxidative degradation of ARB in Fe²⁺/PMS system was investigated.The results are as follows:This paper systematically studied the effect of PCA-PP on the degradation of ARB by iron catalyzed oxidation under different conditions and scenarios.It was found that PCA-PP/Fe²⁺/PMS could have a good activated degradation effect in the coordinated state,and the time-lapse iron loading would change the effect of iron catalyzed oxidation regulated by PCA-PP.Furthermore,the coordination experiment of PCA-PP to Fe²⁺and UV spectroscopy of Fe²⁺in the PCA-PP/Fe³⁺system were conducted to investigate the regulation of Fe activated PMS by PCA-PP,and it was found that the valence state of iron changed constantly in the regulated process.The Peroxysulfate catalyzed oxidation dye characteristics and mechanism of action in the PCA-PP/Fe²⁺/PMS system were investigated,and both the PCA-PP/Fe²⁺/PMS and Fe²⁺/PMS systems were fitted to a first-order kinetic model with kinetic correlation coefficients of 0.991 and 0.997,respectively,and their reaction rate constants were 0.020 min^-1 and0.016 min^-1,respectively.Analysis conclutions using FTIR and XPS techniques indicated that after reacting with PMS,catechol on the surface of PCA-PP was oxidized to quinone structure,both phenolic hydroxyl and carboxyl groups were involved in coordination and chelation,and both Fe（II）and Fe（III）produced coordination effect with PCA-PP.ESR detection and radical quenching experiments showed that so appeared in the PCA-PP/Fe²⁺/PMS system SO₄^·-and·OH radical signals and continuously generated active radicals in an activation reaction of 120 min,while·OH was the major radical in the reaction system.This paper systematically studied the influencing factors of PCA-PP regulating the degradation of acid red B by Fe²⁺activated peroxymonosulfate.A significant inhibition of ARB degradation by NO₂^-and CO₃^2-in PCA-PP/Fe²⁺/PMS systems was found by co existing anion experiments.In addition,the amount of PCA-PP applied,the initial concentration of PMS,and the initial concentration of Fe²⁺were all important factors in the degradation of acid red B by the PCA-PP/Fe²⁺/PMS system.As the number of recycling increased,89%of ARB and 86.9%of PMS could still be decomposed after the 5th cycle use.The phenolic hydroxyl group in poly caffeic acid reduces Fe³⁺to Fe²⁺,maintaining the continuity of PMS decomposition.The complexation of catechol and carboxyl groups in poly caffeic acid to Fe²⁺controls the release rate of Fe²⁺and reduces the quenching of free radicals by Fe²⁺.This study has a certain application potential in promoting the direction of persulfonate catalyzed oxygen degradation of organics.